Hi Jan, are you only talking about A-Z/a-z here? Or Spanish ene, German umlauts, accented letters, etc.?   -----Ursprüngliche Nachricht----- Von:Jan Schultke via Std-Proposals <std-proposals_at_[hidden]> Gesendet:Mo 09.03.2026 10:09 Betreff:Re: [std-proposals] D4039R0 Sequential hexadecimal digits An:C++ Proposals <std-proposals_at_[hidden]>; CC:Jan Schultke <janschultke_at_[hidden]>; I think there's another useful guarantee that could be provided, but I'm not sure whether it should be done as part of this proposal: In any encoding, it looks like alphabetic characters always appear in their lexicographical order, even if they aren't always contiguous.  Consequently, (a <=> b) is meaningful and useful between two characters if you know that a and b are letters. On Sat, 28 Feb 2026 at 10:04, Jan Schultke <janschultke_at_[hidden] <mailto:janschultke_at_[hidden]> > wrote: Hi, https://isocpp.org/files/papers/D4039R0.html  In the recent discussion of D4040R0, it was brought up that C2y now provides the guarantee that hexadecimal digit characters are contiguous. This was done by https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3192%2epdf  I've drafted up a proposal that adopts that guarantee into C++. Feedback is welcome. I expect we can make this a DR against C++98 and pretend it's always been guaranteed.  Jan -- Std-Proposals mailing list Std-Proposals_at_[hidden] https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals